15 research outputs found

    Molecular characterisation of a mycorrhizal inoculant that enhances Trifolium alexandrium resistance under water stress conditions

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    The occurrence of drought is an economically important problem in Morocco. The use of mycorrhizal technology offers a possibility to overcome this problem. A mycorrhizal fungal inoculum “AoufousComplex” isolated in Morocco was shown to enhance Trifolium alexandrium resistance in water deficit situation. The efficiency of this inoculum was confirmed in this study. In order to identify this inoculum, specific primers were used to amplify the 18S subunit. The AluI RFLP typing of the PCR products revealed a single pattern showing no diversity. Phylogenetic analyses of seven sequences including other glomeromycetes allowed an unambiguous identification of the “Aoufous Complex” as Glomus mosseae strains

    Water stress induces overexpression of superoxide dismutases that contribute to the protection of cowpea plants against oxidative stress

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    Water stress is known to induce active oxygen species in plants. The accumulation of these harmful species must be prevented by plants as rapidly as possible to maintain growth and productivity. The aim of this study was to determine the effect of water stress on superoxide dismutase isozymes (SOD, EC 1.15.1.1.) in two cowpea cultivars [Vigna unguiculata L. Walp., cv. Bambey 21 (B21) and cv. TN88-63]. Plants were submitted to water stress by withholding water supply and the expression of SOD was characterized during stress induction. In the same time, photosynthesis characteristics were determinedthrough the measurement of the quantum yield of PS II photochemistry and the energy absorption rate per reaction centre. Results show how water stress regulates the synthesis and the activity of superoxide dismutase isoforms and how these enzymes contribute to protect photosynthesis against the damageable effects of superoxide radicals in cowpea. Increased MnSOD and FeSOD activity and concentration were shown to be induced by water stress and associated with protection of photosystem II photochemistry and whole plant growth against oxidative stress in these plants. On the contrary, plants unable to express high MnSOD and/or FeSOD isoforms showed more sensitivity to water stress

    A Rare third ventricle solitary tuberculoma

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    The localization of the tuberculoma at the third ventricle is rare. The authors report a case of third ventricle solitary Tuberculoma which has occurred in a 10 year old patient and revealed by a syndrome of intracranial hypertension without tuberculosis stigma. This lesion appears clinically and radiologically as a primary brain tumor. A total removal using a subchoroidal approach to the third ventricle has been performed. Histological examination showed a tuberculous like granuloma. An adjuvant antituberculous chemotherapy  practiced for 6 months brought the complete cure. The authors insist on the diagnostic and therapeutic difficulties in front of a third ventricle solitary  tuberculoma

    VariabilitĂ© GĂ©nĂ©tique des Clones de Canne Ă  Sucre PrĂ©sĂ©lectionnĂ©es au Stade Ligne en Nouvelle Plantation Ă  FerkĂ© (Nord CĂŽte d’Ivoire)

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    Objectifs : L’étude visait Ă  caractĂ©riser la diversitĂ© gĂ©nĂ©tique en nouvelle plantation d’un lot de 139 variĂ©tĂ©s de canne Ă  sucre prĂ©sĂ©lectionnĂ©es au stade « une ligne ».MĂ©thodes et rĂ©sultats : Elle a Ă©tĂ© conduite en station expĂ©rimentale, sous irrigation par aspersion en couverture intĂ©grale, au complexe sucrier de FerkĂ© 1, au Nord CĂŽte d’Ivoire. Ces clones ont Ă©tĂ© prĂ©sĂ©lectionnĂ©es en canne vierge parmi 863 clones plantĂ©s par famille, Ă  raison d’un individu par ligne de 3 m de long sans rĂ©pĂ©tition et comparĂ©s Ă  une variĂ©tĂ© tĂ©moin (SP70-1006). Les variables quantitatives et qualitatives relatives Ă  ces clones ont fait l’objet d’une sĂ©rie d’analyses multivariĂ©es. L’étude a montrĂ© que les variables quantitatives permettant de mieux expliquer la diversitĂ© des clones prĂ©sĂ©lectionnĂ©es au stade ligne de 3 m comprenaient, dans l’ordre dĂ©croissant, le poids moyen d’une tige, le diamĂštre moyen des tiges, la longueur moyenne des tiges, le nombre de tiges usinables/3m et le brix. Ces variables ont fortement contribuĂ© Ă  la discrimination de 10 groupes phĂ©notypiques de clones. Les variables qualitatives les plus pertinentes dans la discrimination des groupes concernaient la densitĂ© du tallage et l’intensitĂ© de la floraison.Conclusion et recommandations : Les variables quantitatives permettant de mieux expliquer la diversitĂ© des clones prĂ©sĂ©lectionnĂ©es au stade ligne de 3 m comprenaient, dans l’ordre dĂ©croissant, le poids moyen d’une tige, le diamĂštre moyen des tiges, la longueur moyenne des tiges, le nombre de tiges usinables/3m et le brix. Les variables qualitatives les plus pertinentes dans la discrimination des groupes concernaient la densitĂ© du tallage et l’intensitĂ© de la floraison La variabilitĂ© gĂ©nĂ©tique ainsi rĂ©vĂ©lĂ©e en canne vierge devra ĂȘtre vĂ©rifiĂ©e surtout en 1Ăšre repousse avant la prĂ©sĂ©lection dĂ©finitive des clones pour les deux derniĂšres Ă©tapes du processus de sĂ©lection variĂ©tale Ă  conduire durant 5 ans en plantations commerciales.Mots clĂ©s. SĂ©lection massale, vigueur vĂ©gĂ©tative, stade ligne, nouvelle plantation, variable quantitative, variable qualitative, analyse multivariĂ©e, groupe discriminĂ©, adaptation, agro-Ă©cologie

    DiversitĂ© GĂ©nĂ©tique des PremiĂšres VariĂ©tĂ©s de Canne Ă  Sucre d’Origine RĂ©unionno-Ivoirienne PrĂ©sĂ©lectionnĂ©es Ă  FerkĂ© en CĂŽte d’Ivoire

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    Objectifs: L’étude visait Ă  contribuer Ă  l’amĂ©lioration de la productivitĂ© en culture canniĂšre en CĂŽte d’Ivoire. Plus spĂ©cifiquement, elle visait Ă  caractĂ©riser la diversitĂ© gĂ©nĂ©tique du tout premier lot de 148 variĂ©tĂ©s de canne Ă  sucre d’origine rĂ©unionno-ivoiriennes prĂ©sĂ©lectionnĂ©es au stade « une ligne » en vue d’essais classiques de sĂ©lection de 1Ăšre et 2Ăšme Ă©tapes Ă  conduire par la suite dans les conditions d’exploitation des complexes sucriers de FerkĂ©.MĂ©thodes et rĂ©sultats: Elle a Ă©tĂ© conduite en station expĂ©rimentale, sous irrigation par aspersion en couverture intĂ©grale, au complexe sucrier de FerkĂ© 2, au Nord CĂŽte d’Ivoire. Ces variĂ©tĂ©s ont Ă©tĂ© prĂ©sĂ©lectionnĂ©es en 1Ăšre repousse parmi 985 clones plantĂ©s par famille, Ă  raison d’un individu par ligne de 3 m de long sans rĂ©pĂ©tition et comparĂ©s Ă  une variĂ©tĂ© tĂ©moin (SP70-1006). Celle-ci a Ă©tĂ© plantĂ©e rĂ©guliĂšrement toutes les 5 lignes afin de faciliter la notation des clones pour diffĂ©rents caractĂšres agromorphologiques et phytosanitaires par comparaison avec le tĂ©moin. Les variables quantitatives et qualitatives relatives aux variĂ©tĂ©s prĂ©sĂ©lectionnĂ©es, observĂ©es Ă  la rĂ©colte en 1Ăšre repousse Ă  l’ñge de 10 mois, ont fait l’objet d’une sĂ©rie d’analyses multivariĂ©es. L’étude a montrĂ© que les variables quantitatives permettant de mieux expliquer la diversitĂ© des variĂ©tĂ©s prĂ©sĂ©lectionnĂ©es comprenaient, dans l’ordre dĂ©croissant, le taux de floraison, le nombre de tiges/3m, le diamĂštre des tiges et la longueur des tiges. Ces variables ont fortement contribuĂ© Ă  la discrimination de 8 groupes qui suggĂ©raient une assez bonne diversitĂ© gĂ©nĂ©tique parmi les 148 clones prĂ©sĂ©lectionnĂ©s. Les 4 groupes les mieux reprĂ©sentĂ©s (63,5 % de l’effectif total) comprenaient chacun 20 Ă  30 individus, tandis que les moins reprĂ©sentĂ©s (36.5 %) 11 Ă  15 individus chacun.Conclusion et application des rĂ©sultats: Les variables qualitatives les plus pertinentes dans la discrimination des groupes portent sur trĂšs bon tallage, tallage moyen, port plus ou moins droit, d’une part, et port droit, d’autre part, qui sont associĂ©s, respectivement, aux groupes G1, G7 et G2. Quant aux variables port penchĂ© et port en bataille qui sont Ă©galement pertinentes, elles semblaient ĂȘtre associĂ©es Ă  6 groupes Ă  la fois (G2, G3, G4, G5, G6, G8). La variabilitĂ© gĂ©nĂ©tique ainsi rĂ©vĂ©lĂ©e est nĂ©cessaire aux prochains essais de sĂ©lection prĂ©vus en plantations commerciales.Mots clĂ©s: SĂ©lection massale, vigueur vĂ©gĂ©tative, stade ligne, variable quantitative, variable qualitative, analyse multivariĂ©e, groupe dissemblable, adaptation, contexte agro-Ă©cologiqueEnglish Title: Genetic Diversity of First Sugarcane Varieties of Reunion-Ivorian Origin Preselected in FerkĂ©, Ivory CoastEnglish AbstractObjectives: The overall study objective was to contribute to sugarcane yield improvement in Ivory Coast. It aimed to characterize the genetic diversity of the first batch of 148 sugar cane varieties of Reunion-Ivorian origin preselected at the "one-row" stage for standard selection trials of 1st and 2nd stages to be carried out under FerkĂ© commercial field conditions.Methodology and results: It was conducted on FerkĂ© 2 experimental station under full sprinkler irrigation in northern Ivory Coast. These varieties were pre-selected in 1st regrowth among 985 clones planted per family, one individual per row 3 m long without repetition and compared to a control variety (SP70-1006).That one was replicated several times every 5 rows to ease agronomics observations of clones in comparison with the control. Quantitative as well as qualitative traits observed at the age of 10 months were subjected to a series of multivariate analyses. The study showed that quantitative traits, which better explained diversity of varieties, were the following in decreasing order: flowering rate, number of millable stalks/3m, stalk diameter, and stalk height. Those phenotypic traits highly contributed to discrimination of varieties into 8 clusters, which suggested a good genetic diversity among all 148 preselected clones. Four best-represented clusters (63.5 % of total) comprised 20-30 individuals each, whereas less represented clusters (36.5 %) involved 11-15 individuals each.Conclusion and application of results: Quantitative traits most relevant in variety clustering were high tillering, moderate tillering, erect traits, which were associated respectively with clusters G1, G7 and G2. As for lodging traits, they were associated with 6 clusters all together, namely G2, G3, G4, G5, G6 and G8. The genetic variability so shown is a prerequisite for further selections trials under commercial field conditions.Keywords: visual selection, vegetative vigor, one-row stage, phenotypic trait, multivariate analysis, clustering, adaptation, agro-ecologic conditio

    Intersporal Genetic Variation of Gigaspora margarita, a Vesicular Arbuscular Mycorrhizal Fungus, Revealed by M13 Minisatellite-Primed PCR

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    Spores of vesicular arbuscular mycorrhizal (VAM) fungi contain thousands of nuclei. In order to understand the karyotic structure of a VAM fungus spore, the genetic variation of the first generation of spores from a VAM fungus (Gigaspora margarita) was examined. Spores originating from both single- and multispore inoculations of the species G. margarita were analyzed by M13 minisatellite-primed PCR. In both cases, different fingerprints were obtained from individual spores with few spores exhibiting similar fingerprints. These results can be explained only by a heterokaryotic status of the nuclear population within a spore

    Unchain My EL Reasoner

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    We study a restriction of the classification procedure for EL++ where the inference rule for complex role inclusion axioms (RIAs) is applied in a ``left-linear'' way in analogy with the well-known procedure for computing the transitive closure of a binary relation. We introduce a notion of left-admissibility for a set of RIAs, which specifies when a subset of RIAs can be used in a left-linear way without loosing consequences, prove a criterion which can be used to effectively check this property, and describe some preliminary experimental results analyzing when the restricted procedure can give practical improvements
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